Crate butcher

Butcher

An easy way to interact with Cowed structs and enums.

This crate proposes some simple solutions to the most common patterns I met while working with Cows in Rust. It currently fixes two patterns: destructuring and iteration related to objects wrapped in Cow.

Destructuring

The Butcher trait can be used when it is necessary to destruture something wrapped in a Cow. Below is a simple example:

use std::borrow::Cow;
use butcher::Butcher;

#[derive(Butcher, Clone)]
struct MyNumberList {
    val: u32,
    next: Option<Box<MyNumberList>>,
}

fn destructure_list_elem(i: Cow<MyNumberList>) -> (Cow<u32>, Cow<Option<Box<MyNumberList>>>) {
    let ButcheredMyNumberList { val, next } = Butcher::butcher(i);

    (val, next)
}

The Butcher procedural macro can be derived for structs and for enums.

Iteration

Here is a demonstration of how to iterate over an object wrapped in a Cow:

use std::borrow::Cow;
use butcher::iterator::{CowIter, IntoCowIterator};

fn print_numbers(elems: Cow<[u32]>) {
    let mut iter = elems.into_cow_iter();

    for element in iter {
        // The type of element is Cow<u32>
        println!("{:?}", element);
    }
}

See the documentation of CowIter for more information.

Modules

deriving_butcher_enum	Quick introduction to butchering on enums
deriving_butcher_struct	Quick introduction to butchering on structs
iterator	An iterator over data wrapped in Cow.

Macros

butcher_struct

Allow simple destructuring.

Traits

Butcher
ButcherField

Derive Macros

Butcher

Derives the Butcher trait for a structure or an enum.